Question

8. Program Timer O in C to generate a square wave of 0.5 KHz. Assume that XTAL 11.0592 MHz #include sbit mybit P1A5; void delay (void); void main (void) while (1) ( mybit - delay(0): void delay (void) TMOD TLO = THO TRO = 1; while (ITFO); TFO = 0;

Answer 1

XTAL = 11.0592 MHz ; the counter counts up for each 1.085 us.So,in order to make a square wave of 0.5 Khz i.e 2 ms flipping period.

We need 2 ms/1.085 us = 1843 clocks.To acheive this many clocks; we need to load values into TL and TH :-

65536 - 1843 = F8CDH .So, TH = F8 and TL = CD

Program :-

#include<reg51.h>

sbit mybit = P1^5;

void delay(void);

void main(void){

while(1){

mybit=~mybit;

delay();

}

}

void delay(void){

TMOD = 01;

TL0 = 205;

TH0 = 248;

TR0 = 1;

while(!TF0);

TR0=0;

TF0=0;

}